Intravascular infections

Question 1

transient bacteremia

Answer 1

clearance exceeds entry

source is local infection somewhere

Question 2

continuous bacteremia

Answer 2

seeding exceeds clearance capacity

Question 3

septicemia

Answer 3

clearance mechanisms subverted

Question 4

in infective endocarditits is there a continuous concentration in the blood or does is go up and down?

Answer 4

continuous concentration of bacteria in the blood

Question 5

what are the four endovascular infections

Answer 5

infective endocarditis
infected thrombus
mycotic aneurysm
infections of intravascular devices

Question 6

predispositions of IE

Answer 6

congenital heart disease
Rheumatic heart disease
conditions leading to bacteremia
IV drug abuse
Hopitalization

Question 7

prior to antibiotic era what was the fatality rate of IE?

Answer 7

100%

Question 8

Pathogenesis of IE

Answer 8

• turbulent blood flow
• Endothelial cell activation
• Fibrin and platelet deposition
• Silent of clinical bacteremia seed sterile vegetations
• bacteria grow within fibrin vegetations

Question 9

what is unique about the endocardium including valves, chordae, papillary muscle and atria that make them prime for immune evasion of bacteria?

Answer 9

they receive their nourishment from the blood stream and DO NOT have capillaries. Neutrophils require capillaries to get to infection site.
**Thus innate and acquired immune mechanisms are subverted.

Question 10

observations of IE in vivo

Answer 10

bacteria imbedded within vegetations are impossible to entirely eradicate
*IE is characterized by unrestricted microbial replication within vegetations leading to in vivo bacterial colonies

Question 11

Diagnosis: Duke Criteria

major findings

Answer 11

• continuous bacteremia

- target lesion on valve, supports or endocardium by (ECHO or new murmur)

Question 12

Diagnosis: Duke Criteria

minor findings

Answer 12

fever
predisposing heart condition
IV drug user
embolic phenomena
immunological phenomena

Question 13

signs of IE

Answer 13

tender Osler nodes
non tender Janeway lesions
Roth spot in eye
Conjunctival petechiae

Question 14

Microbiology of IE

Answer 14

• staphylococci-S. aureus, coagulase neg staph spp.
• streptococci-viridans spp. and gamma strep
• Enterococci
• Gram negative bacilli
• Fungi

Question 15

are more virulent and less virulent species going to cause IE?

Answer 15

less virulent

mostly Strep. mutans, where as S. pyogenes doesn’t causes much IE

Question 16

clinical correlation

Answer 16

congestive heart failure
stroke
infarcts
glomerulonephritis
mycotic aneurysms
abscesses(local or distant)

Question 17

what dental procedures give the highest bacteremia values?

Answer 17

periodontal surgery 88%
extraction 60%
Brushing or irrigation device 40%

Question 18

high risk adverse outcome from IE

Answer 18

• prosthetic heart valve or prosthetic material inserted for repair
• previous infective endocarditis
• congenital heart disease
• cardiac treatment patients who develop valvulopathy

Question 19

how do you prevent IE

Answer 19

prophylactic antibiotics prior to procedures for those with:
-prosthetic heart valves
-previous IE
-congenital heart diseases
-heart Tx with valvulopathies 
IV or PO regimens at time of procedures

Question 20

treatment of IE

Answer 20

IV therapy
-bactericidal regimen
length of treatment-2,4,6,8 wks
test for antibiotic sensitivity 
Surgery